III.B.3.b. (XIII.C.2.)

Vibrational frequency scaling factors

Calculated vibrational frequencies ("theory" in table) are calculated at ROHF/6-311G*

Scale factor	How many		Source
	Molecules	Vibrations
0.856 ± 0.159	36	57	cccbdb

Jump to histogram

Formula	Name	Mode	Symmetry	Frequency			Count
				Theory	Experiment	ratio	molecules	vibrations
CF3	Trifluoromethyl radical	1	A1	1214	1089	0.897	1	1
		2	A1	766	701	0.915	1	2
		3	E	1421	1260	0.887	1	3
		4	E	561	509	0.906	1	4
HCO	Formyl radical	1	A'	2970	2434	0.820	2	5
		2	A'	2147	1868	0.870	2	6
		3	A'	1269	1081	0.852	2	7
C3H3	Propargyl radical	1	A1	3632	3322	0.915	3	8
		6	B1	737	687	0.932	3	9
		7	B1	472	490	1.038	3	10
HO2	Hydroperoxy radical	1	A'	4090	3436	0.840	4	11
		2	A'	1659	1392	0.839	4	12
		3	A'	1269	1098	0.865	4	13
CH	Methylidyne	1	Σ	3065	2861	0.933	5	14
		1	Σ	3065	3145	1.026	5	15
		1	Σ	3065	2931	0.956	5	16
OH	Hydroxyl radical	1	Σ	4054	3738	0.922	6	17
NF2	Difluoroamino radical	1	A1	1276	1075	0.843	7	18
		2	A1	673	573	0.852	7	19
		3	B2	1189	942	0.793	7	20
CF	Fluoromethylidyne	1	Σ	1403	1308	0.932	8	21
CCl	carbon monochloride	1	Σ	863	877	1.016	9	22
SiF	silicon monofluoride	1	Σ	886	857	0.968	10	23
SiN	Silicon nitride	1	Σ	1326	1151	0.869	11	24
LiO	lithium oxide	1	Σ	868	815	0.938	12	25
BS	boron sulfide	1	Σ	1263	1180	0.934	13	26
AlS	Aluminum sulfide	1	Σ	683	617	0.903	14	27
CP	Carbon monophosphide	1	Σ	1461	1240	0.849	15	28
NaO	sodium monoxide	1	Σ	524	492	0.939	16	29
BeF	Beryllium monofluoride	1	Σ	1273	1247	0.980	17	30
PH2	Phosphino radical	1	A1	2529	2310	0.913	18	31
		2	A1	1254	1102	0.879	18	32
SiH3	silyl	1	A1	2329	2136	0.917	19	33
		2	A1	897	728	0.812	19	34
		3	E	2340	2185	0.934	19	35
		4	E	1017	922	0.907	19	36
NH2	Amino radical	1	A1	3636	3219	0.885	20	37
		2	A1	1718	1497	0.872	20	38
		3	B2	3722	3301	0.887	20	39
NH	Imidogen	1	Σ	3571	3283	0.919	21	40
		1	Σ	3571	3314	0.928	21	41
SiH	Silylidyne	1	Σ	2138	2043	0.955	22	42
BeCl	beryllium chloride	1	Σ	844	847	1.003	23	43
SH	Mercapto radical	1	Σ	2810	2696	0.959	24	44
SiCl	Clorosilylidyne	1	Σ	517	536	1.037	25	45
PH	phosphorus monohydride	1	Σ	2498	2364	0.946	26	46
		1	Σ	2498	2415	0.967	26	47
		1	Σ	2498	2403	0.962	26	48
MgH	magnesium monohydride	1	Σ	1580	1493	0.945	27	49
BH2	boron dihydride	2	A1	1125	954	0.848	28	50
AlH2	aluminum dihydride	1	A1	1975	1770	0.896	29	51
		2	A1	823	760	0.924	29	52
		3	B2	1986	1807	0.910	29	53
MgF	Magnesium monofluoride	1	Σ	743	712	0.958	30	54
MgCl	magnesium monochloride	1	Σ	456	462	1.013	31	55
ClO	Monochlorine monoxide	1	Σ	841	854	1.015	32	56
PF	phosphorus monofluoride	1	Σ	869	847	0.974	33	57
BeOH	beryllium hydroxide	2	A'	1319	1246	0.944	34	58
S2	Sulfur diatomic	1	Σg	801	726	0.906	35	59
ClS2	Sulfur chloride	1	A'	567	662	1.168	36	60
		2	A'	519	450	0.866	36	61
		3	A'	239	196	0.822	36	62

How do we calculate the scaling factor?

Histogram of vibrational frequency ratios

Ratios greater than 1.35 are in the 1.35 bin. Ratios less than 0.7 are in the 0.7 bin.

	20
	15
	10
	5
	0
		0.70			0.75			0.80			0.85			0.90			0.95			1.00			1.05			1.10			1.15			1.20			1.25			1.30			1.35
Ratio of experimental frequency to calculated frequency